The present invention relates to disk-type ultra-high frequency antenna arrays, more particularly associated with radars carrying out measurements of angular deviation.
The disk-type antenna array is known. In its present form, such an antenna comprises a cylindrical cavity of large diameter and small thickness. One of the faces of this cavity is connected at its center to a circular section guide, the other face is provided with elementary antennae, spread out along concentric circles and coupled electromagnetically with the inside of the cavity. When transmitting, the circular guide is then fed with an electromagnetic wave in the TM.sub.01 mode which generates in the cavity a circular radial wave.
The circular guide is connected to a T delivering on reception on at least two distinct channels the summing .SIGMA. and difference .DELTA. signals required for elaborating the angular deviation measurement signal .epsilon.. For transmitting it is the summing channel of this T which receives the electromagnetic wave transmitted to the disk-type antenna array.
This type of embodiment presents several drawbacks due to the required use of a TM.sub.01 mode wave; in fact, a wide frequency band and a high power level are difficult to obtain because of the requirement of energizing the antenna in the TM.sub.01 mode. This latter is generally obtained by means of the difference channel of a magic T connected to the summing channel of the T of the antenna, this difference channel being difficult to match and having poor power behavior.